Toilets are constructed with bowls to receive human excrement and tanks that hold water for the purpose of clearing the excrement from the bowl. They generally have a valve movable between an open and a closed position. The valve is connected to a flush linkage which draws the valve into the open position upon activation of a flushing lever. A standpipe is provided which serves to prevent the toilet tank from overflowing. It is generally accepted that when a toilet is flushed more water is released from the tank than is required to clear the bowl.
To address the problem of excess water usage, a plurality of water conservation devices have been developed. Examples of such water conservation devices are U.S. Pat. No. 4,748,699 which issued to Charles F. Stevens in 1988 and U.S. Pat. No. 4,945,578 which issued to Mohamed A. Jomha and Andrew Lazowski in 1990. These patents disclose floatation devices which travel up and down on the standpipe of the toilet and push the valve into the closed position.
Water conservation devices which "push" the valve into a closed position have a number of inherent problems. One problem is that they are relatively complex. Another problem is that they are difficult to install on some styles of toilets. A final problem is that the valve occasionally becomes jammed in a partially open position resulting in gallons of water flowing through the tank.